The inelastic neutron scattering spectrum of rotational tunnelling in phase III of NH4PF6
Abstract
The first example of tunnelling of an ammonium ion under C2 rotational symmetry is described, i.r. spectroscopy having previously suggested higher symmetries; the inelastic neutron scattering (i.n.s.) spectrum shows extra intensity in the near-elastic region as well as unexpected peak broadening and two interpretations of the observed i.n.s. spectrum are discussed.